Oil Pressure Warning

[Frederick Stienheld]

Does anyone know at what pressure (PSI or Kpa) the oil warning light comes on?

I'm setting up a LCD display/monitor/control system and want to know what to set the lower threshold warning beeper at.

[S N 3 A K Y]

Not the exact information you are chasing, but a helpful reply is better than no reply (or a smart-arse one).
According to the Gregory's manual,
Oil Pressure is:

At Idle........... 49kpa (7psi)
At 2800rpm........ 390 - 490kpa (47 - 71psi)


S N 3 A K Y

[Josh]

silly people. You oil pressure changes depending on how hot your oil is. For instance when I start my car up early in the morning (when it's still dark) my oil pressure is about 450 @ 1000rpm. and it will sit on this until I have been driving for roughly umm 20 mins or so then the oil pressure gauge will start to go up and down depending on the rpm. By the way my engine has only done about 1000km's so your engines may be different. i think the minimum oil pressure I have seen the VDO gauge at after going for a big drive at idle is about 220 kpa and if i rev her up the gauge will stop at 490kpa because the relief valve opens to stop excess oil pressure (excess oil pressure can "spin bearings" and so forth)

Hope this kinda helps

Josh

[S N 3 A K Y]

I think you have misinterpreted the question, the post was asking what the oil starvation point was in the lubricating system. It's common knowledge that the pressure rises and falls with rpm and/or load on the engine.

"Does anyone know at what pressure (PSI or Kpa) the oil warning light comes on?"
"I'm setting up a LCD display/monitor/control system and want to know what to set the lower threshold warning beeper at"

In simple terms, what is the lowest PSI/KPA that oil pressure should not drop below to maintain health and longevity of the engine.
With this information he can program a warning light/beep into his computer to avoid running on a dry sump or overheating the bearings etc while driving.
You may look at the oil pressure gauge moving around every now and then, the light/beep is an excellent safety warning for peripheral vision as you cant drive with your eyes constantly glued to the needle on the gauge.
Like they say on the titty cancer adds on tele - "Early detection is the best prevention for the worst case scenario"...


"when I start my car up early in the morning (when it's still dark) my oil pressure is about 450 @ 1000rpm. and it will sit on this until I have been driving for roughly umm 20 mins or so"

"i think the minimum oil pressure I have seen the VDO gauge at after going for a big drive at idle is about 220 kpa"

This is the kind of info he is chasing.



S N 3 A K Y

[Frederick Stienheld]

Thanks for that Sneaky and Josh.

Sneaky I usually sit on around 20psi at Idle so I guess I dont have any worries there, I'll set my warning at 7 I spose.

[Adam]

It is a good practice on racecars to fit a 'low pressure' oil warning light in place of the 'no pressure' warning light fitted to roadcars. If your engine had 8 psi (so the no pressure light would not trigger) and were giving the engine a hard time then you'd probably have metal to metal contact in the big ends and mains and lunch your engine pretty quickly.

The problem is, any warning that will save your engine, will go off continuously at idle.

[Frederick Stienheld]

True
well I can easily link it up to rpm so that at idle it will warn at 7psi or the likes, and above a few thousand it will go off at 40 or so

[Poida]

From what you say in your last post, you have the opportunity to set different pressures for different rpm's. Follow the guidelines in the Gregory's manual for now and if you later find more presise specs go with them. Now if you are setting it up for a performance engine that idles at greater revs then the Gregoy's info is nul and void. You really may need to run a temporary oil guage to plot the pressure under different conditions then use the data to calibrate your device.



Why would someone say that high oil pressure spins bearings??

Pressure is pressure. Don't confuse it with volume. In reality you need greater volume of flow and a little more pressure if the engine is working harder than designed. You also need a greater capacity storage facility (sump in most cases), more oil and a thermostaticly controlled oil cooler as well.
_________________
I try to tackle one day at a time, but often several days attack me at once.



(The views I present are my own and NOT necessarily of the administrators or other members of this site.)

[Highlander]

im guessing theres no high volume oil filters available for a 1600 or g200 the 1600 code is z56b i think